Radiator replacement

[David T]

Oh, I read that it was brass on the DMC knowledge base site. http://support.delorean.com/kb/a44/radiator.aspx



How does the thermostat affect the efficiency the cooling? I didn't get much time to elaborate on my testing condition, but it would simulate sitting at idle in 70F ambient temp. As stated, CFM is difficult to calculate, so it would be easier to see how long it would take a stock setup to cool the running coolant from 220F to 150F vs a new setup in identical conditions. That way you eliminate the need to calculate CFM. If it takes both setups the same amount of time to cool the system, then you know even if the new fans have less CFM you have the same cooling efficiency as the stock setup with less current draw. I don't see why you would focus on one part of the system when you are changing at least 2.

Anyways, my fans don't seem to turn on when the temp is high enough, so Derek you mind helping me change out my fans??

If you can imagine an "ideal" radiator and the temp of the coolant going in was 250 and coming out was 70 the motor would not be able to run hot enough. It is designed to operate at about 180 so there is a device called a thermostat which is a valve that stops the water from going to the rad so the coolant (and the motor) will heat up. Once it gets to the right temperature the thermostat opens and sends the coolant to the rad to be cooled. When the thermostat is closed the fans don't need to run. Now add this, when the thermostat opens and sends the hot coolant to the rad for cooling the fans still aren't running. The fans only run when the Otterstat switch gets hot enough to turn the fans on. That way if you are moving fast enough, you don't need the fans so the O switch keeps the fans off. All of this stuff is designed so as to work together in harmony to keep the motor's temperature in a narrow operating band where it is most efficient. Making one part of this system different from what was designed can change the way the whole thing operates. Like most things you must approach it from a "systems" design and understand how each part operates as part of a larger system before tinkering with one part.

[steve]

All I know is that with the OEM fans it took X minuets to cool and shut down. This was tested over and over.
The new Low Voltage High Efficiency fans take 1/2 of X to cool and shut down. This was tested over and over.

I don't get the argument.
Steve

[mr_maxime]

When testing something you don't need a full working system for a proper test. I mean you could test it with the thermostat and otterstat as well if you wanted to, but I just dont see the point if their purpose to to stop coolant flow or turn fans on or off. Those are both functions that could be tied back to the controller running the test. You could set the pump to kick on at whatever temperature you want and same with the fans. You could even do R&D that way to optimize at what temp the thermostat and otterstat should work for optimal engine temp. Seeing as how CFM impacts how quickly a radiator would cool, I was just isolating the fans and radiator because both are being changed. You could easily set a thermal probe at the inlet and outlet of the radiator as well to see the difference between stock and new. Testing the system when coolant is not running and fans are off doesnt really matter if youre trying to make sure if a lower CFM fan provides adequate flow to cool the coolant to normal operating conditions. This, I think would be more accurate than simply using specs that aren't easily measured and saying lower CFM is a step back when the efficiency of a new radiator isnt tested along it. I understand that all of this stuff must work in harmony to keep the engine running properly and must take a system approach to see how they function together, which I why I suggested testing the fans on the radiator as opposed to simply comparing CFM. If you're not changing out the radiator, then of course CFM comparison might be sufficient.

All I know is that with the OEM fans it took X minuets to cool and shut down. This was tested over and over.
The new Low Voltage High Efficiency fans take 1/2 of X to cool and shut down. This was tested over and over.

This X all I'm trying to test minus a whole car cause its easier without risk of overheating the engine.

[Henrik]

For those who have to do a radiator replacement, what other parts do you recommend having for a complete replacement (aside from the radiator itself obviously)? I ask because sometime down the road, I'll have to do one.
Thanks in advance!

-Chris

To get back to Chris' initial question... or more like a "lessons learned" type of thing: When I replaced my stock radiator with a DMC aluminum ditto I should have removed the condenser too. Sure, it is possible to do it with the condenser in place but it was a royal pain. In my mind it's worth an AC evacuation/vacuum/recharge to keep the radiator's aluminum fins from getting crushed.

[David T]

When testing something you don't need a full working system for a proper test. I mean you could test it with the thermostat and otterstat as well if you wanted to, but I just dont see the point if their purpose to to stop coolant flow or turn fans on or off. Those are both functions that could be tied back to the controller running the test. You could set the pump to kick on at whatever temperature you want and same with the fans. You could even do R&D that way to optimize at what temp the thermostat and otterstat should work for optimal engine temp. Seeing as how CFM impacts how quickly a radiator would cool, I was just isolating the fans and radiator because both are being changed. You could easily set a thermal probe at the inlet and outlet of the radiator as well to see the difference between stock and new. Testing the system when coolant is not running and fans are off doesnt really matter if youre trying to make sure if a lower CFM fan provides adequate flow to cool the coolant to normal operating conditions. This, I think would be more accurate than simply using specs that aren't easily measured and saying lower CFM is a step back when the efficiency of a new radiator isnt tested along it. I understand that all of this stuff must work in harmony to keep the engine running properly and must take a system approach to see how they function together, which I why I suggested testing the fans on the radiator as opposed to simply comparing CFM. If you're not changing out the radiator, then of course CFM comparison might be sufficient.



This X all I'm trying to test minus a whole car cause its easier without risk of overheating the engine.

The last time I heard the logic that you don't need an "end-to-end" full systems test was NASA when they first sent up the Hubble telescope. We all know how that one turned out! You will quickly find out if you accounted for ALL of the variables.

[DMC02566]

For those who have to do a radiator replacement, what other parts do you recommend having for a complete replacement (aside from the radiator itself obviously)? I ask because sometime down the road, I'll have to do one.
Thanks in advance!

-Chris

First I would recommend taking contortionist classes or training a small handed monkey to reach into the small spaces you will have to work. I did mine with the car on ramps and found it difficult to get my big mitts into the space. Take your time. If you look at how the car was built, the radiator was in place before the body and a bunch of other stuff.

Take a look at all of your hoses as they may be the originals and in need of replacement and it would be a shame to finish the radiator replacement only to loose coolant to an old hose breaking. When I purchased my car in 2006 it still had original hoses under the car. This job takes about all day with the car on a lift.

Good Luck,

Lee Edmonson
# 02566

[Chris 16409]

I just noticed that my radiator has sprung a leak. It's only a few years old too. I'm going to get one of Ed Uding's from DMC-EU. I have a friend who has one and swears by it. I hate having to do a job over again because of a faulty part. There's a hole somewhere in the thing. I found coolant sprayed on the box covering the washer fluid bottle.

[ed uding]

To make it all simple, this is what you shoot see for.

Radiator: you have some options. But the old stock one, with the plastic chambers is no option to drive any more.
Cooling fans: stock and upgrade, ( with a good Radiator the new style Fans can do the job any way) Performance v8 engine's stay still cool with the right Radiator.
Water pipe's: inspect the inside of the pipe just where the clamp was on the outside, on this spot you start to see small put holes. perfect time to replace it now.
Thermostat: we still see them without the small pin that hold the small hole open to bleed the system. (Test it by push the RH water hose from the waterpump flat, you can do it a couple of time. Now you can hear the pin moving inside, if so you are ok.
If not, bay a new one with a new rubber gasket, and no dirty silicone.
Inspect the condensor, it the aluminium between the cores is bend to heavy, it block the air flow. you can bend it back with a small screw driver, but there is always a risk to brake it. The aluminium is weak and oft rusty.

Best way if you have time, is to strip the system down. Make your list and bay what you neat.

Regards Ed
www.delorean.eu

[cdrusn]

I just noticed that my radiator has sprung a leak. It's only a few years old too. I'm going to get one of Ed Uding's from DMC-EU. I have a friend who has one and swears by it. I hate having to do a job over again because of a faulty part. There's a hole somewhere in the thing. I found coolant sprayed on the box covering the washer fluid bottle.

Borrow a cooling system pressure tester from auto zone or O'Reillys and pressurize the system and see where the leak is. Might be a hose and not the radiator especially one so new.